Electromagnetic locking mechanism

ABSTRACT

An electromagnetic locking mechanism including (a) a rotary lock bolt ( 65 ) rotatably reciprocable between a normally protruding locking position and a retracted unlocking position on a forced rotation thereof by an external opening force; (b) a lock bolt urging member ( 67 ) in continuous abutting engagement with the rotary lock bolt ( 65 ) and linearly reciprocable between a normally outwardly biased position for urging the rotary lock bolt ( 65 ) to its normally protruding locking position and a retracted position on the forced rotation of the rotary lock bolt ( 65 ); and (c) a blocking member ( 131 ) reciprocable between a blocking position in the normally protruding locking position of the rotary lock bolt ( 65 ) and an unblinking position for respectively preventing and enabling a rearward displacement of the lock bolt urging member ( 67 ) from its normally outwardly biased position to its retracted position on the forced rotation of the rotary lock bolt ( 65 ).

This application is the national phase under 35 U.S.C. §371 of PCTInternational Application No. PCT/IL99/00148 which has an Internationalfiling date of Mar. 17, 1999, which designated the United States ofAmerica.

FIELD OF THE INVENTION

The invention relates to electromechanical locking mechanisms in generaland in particular to electromechanical locking mechanisms having arotary lock bolt.

BACKGROUND OF THE INVENTION

In U.S. Pat. No. 5,134,870 to Uyeda et al, there is illustrated anddescribed an electromagnetic locking mechanism including a rotary lockbolt governing the locking and unlocking of a door via a handle drivenbolt works mechanism having a bolt works member reciprocable betweenfirst and second operative positions respectively corresponding tolocked and unlocked states of the door. Alternative implementations ofthe electromagnetic locking mechanism are required, each suitable foruse with either one or the other of a clockwise and a counterclockwiseoperative bolt works mechanism.

The rotary lock bolt is urged into a normally protruding lockingposition by a biasing spring whereby it is transversely disposed in thepath of the bolt works member which slidingly abuts there against toforciby rotate the former to a substantially retracted unlockingposition on the latter's displacement from its first operative positionto its second operative position. To prevent an unauthorized opening ofthe door, rotation of the rotary lock bolt is stopped by means of asolenoid armature which is retracted on entry of an access code via adigital keypad entry device. To avoid undue shear stress on the solenoidarmature during an attempted unauthorized opening i.e. when the solenoidarmature is extended, the rotary lock bolt is provided with a safetynotch which engages a safety key after the rotary lock bolt rotatesslightly about its point of contact with the solenoid armature.

In operation, the biasing spring undesirably presents an increasingresistance from the initial contact between the bolt works member andthe rotary lock bolt until the free passage of the bolt works member toits second operative position. Secondly, there is undesirable play inthe bolts works mechanism before engagement between the safety notch andsafety key. Lastly, engagement between the safety notch and the safetykey may leave the bolt works mechanism inoperable in a so-called“deadlock state” due to the biasing spring not returning the rotary lockbolt to its normally protruding locking position on the returndisplacement of the bolt works member to its first operative position.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention, there isprovided an electromagnetic locking mechanism comprising:

(a) a rotary lock bolt rotatably reciprocable between a normallyprotruding locking position and a retracted unlocking position on aforced rotation thereof by an external opening force;

(b) a lock bolt urging member in continuous abutting engagement withsaid rotary lock bolt and linearly reciprocable between a normallyoutwardly biased position for urging said rotary lock bolt to saidnormally protruding locking position and a retracted position on saidforced rotation of said rotary lock bolt; and

(c) a blocking member reciprocable between a blocking position in saidnormally protruding locking position of said rotary lock bolt and anunblocking position for respectively preventing and enabling a rearwarddisplacement of said lock bolt urging member from said normallyoutwardly biased position to said retracted position on said forcedrotation of said rotary lock bolt.

An electromagnetic locking, mechanism of the present invention isadapted for installation in a conventional manner in safes, vaults,strong rooms and the like having a handle driven bolt works mechanism asdescribed hereinabove, namely, with a bolt works member for forciblyrotating the rotary lock bolt from its normally protruding lockingposition to its retracted unlocking position on entry of an access code.In a simplified construction, an electromagnetic locking mechanism ofthe present invention is suitable for use with only one type ofoperative bolt works mechanism, namely, either a clockwise or acounterclockwise operative bolt works mechanism. In a modifiedconstruction of an electromagnetic locking mechanism of the presentinvention, the positions of the rotary lock bolt and bolt lock urgingmember are interchangeable such that the electromagnetic lockingmechanism can be installed in either a clockwise or a clockwise boltworks mechanism. An electromagnetic locking mechanism of the presentinvention as can other constructions of electromagnetic lockingmechanisms with rotary lock bolts, for example, as illustrated anddescribed in the aforementioned U.S. Pat. No. 5,134,870 can bepreferably adapted for installation in typically smaller safes and thelike which are locked and unlocked directly by a handle operated lock.

The rotary lock bolt has a cam surface in continuous abutting engagementwith an abutment surface of the lock bolt urging member which isinclined with respect to the latter's direction of linear reciprocation.The lock bolt urging member is preferably normally outwardly urged by abiasing spring acting against a trailing portion thereof andcompressible in a direction co-directional with the lock bolt urgingmember's rearward displacement. A solenoid armature constituting ablocking member of the stopping means is preferably linear reciprocablein a direction perpendicular to the lock bolt urging member's linearreciprocation. The solenoid armature is operatively associated with alock bolt arresting member which is integrally formed with the lock bolturging member in the simplified construction of the electromagneticlocking mechanism of the present invention and which is detachabletherefrom in the modified construction of the electromagnetic lockingmechanism of the present invention adaptable for use in either aclockwise or a counter clockwise operative bolt works mechanism. Thesolenoid armature is selectively reciprocable between an outwardlybiased blocking position in the normally outwardly biased position ofthe lock bolt urging member and a retracted unblocking position enablingthe rearward displacement of the lock bolt urging member. The solenoidis preferably a magnetically latched solenoid whilst the code entrymeans is preferably implemented by the data receiving means as describedin PCT/IL98/00105. An electromagnetic locking mechanism of the presentinvention fitted with long life batteries can have a useful life ofseveral years during which it can is be operated many thousand of times.

In operation, the solenoid armature is retracted on entry of an accessfor sufficient time for an external opening force applied to the rotarylock bolt to compress the biasing spring during the rearwarddisplacement of the lock bolt urging member from its normally outwardlybiased position to its retracted position. By virtue of the cammingaction gradually acting over a longer arm as the rotary lock bolt isgradually forced to its retracted unlocking position, the force requiredto compress the biasing spring correspondingly gradually becomes less.The solenoid armature presents a virtually immediate positive blockingaction to an attempted unauthorized opening and also precludes thepossibility of a deadlock situation from arising. In an attemptedunauthorized opening of a door, the force applied against the rotarylock bolt acts internal supporting structures thereby considerablyreducing the force directly applied against the solenoid armature.

In accordance with a second aspect of the present invention, there isprovided an electromagnetic locking mechanism comprising:

(a) a rotary lock bolt rotatably reciprocable between a normallyprotruding locking position and a first retracted unlocking position ona forced rotation thereof by an external opening force;

(b) a handle operated carriage linearly reciprocable between outward andinward positions for selectively displacing said rotary lock boltbetween said normally protruding locking position and a second retractedunlocking position; and

(c) a blocking member reciprocable between a blocking position in saidnormally protruding locking position of said rotary lock bolt and anunblocking position for respectively preventing and enabling a rearwarddisplacement of said carriage from said outward position to said inwardposition.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the different aspects of the presentinvention and to show how the same can be carried out in practice, apreferred embodiment will now be described, by way of a non-limitingexample, with reference now made to the accompanying drawings, in which:

FIGS. 1 and 2 are pictorial representations of the inside surfaces ofsafe doors locked and unlocked by a counter clockwise operative handledriven bolt works mechanism and directly by a handle, respectively;

FIGS. 3 and 4 are partly exploded close-up front and rear views of alock having an electromagnetic locking mechanism of the presentinvention for installation on either one of the safe doors of FIG. 1 or2;

FIGS. 5, 6 and 7 are close-up, top and front views of the lock bolt ofthe electromagnetic locking mechanism of the present invention,respectively;

FIGS. 8 and 9 are cross section views along lines VIII—VIII and IX—IX inFIG. 5, respectively;

FIGS. 10 and 11 are exploded views of the electromagnetic lockingmechanism of the present invention with different construction lines;

FIGS. 12 and 13 are partly cut away views of the lock of FIGS. 35 and 4in partially assembled and fully assembled states, respectively;

FIGS. 14 and 15 are cross section views along lines XIV—XIV and XV—XV inFIG. 13, respectively;

FIG. 16 is a perspective view of the lock of FIGS. 3 and 4 with itsrotary lock bolt and its lock bolt urging member reversed for use with aclockwise operative handle driven bolt works mechanism;

FIGS. 17A-17F illustrate a complete sequence of operation for unlockingand locking the safe door of FIG. 1;

FIGS. 18A-18E illustrate a complete sequence of operation for thelocking and unlocking of the safe door of FIG. 2;

FIGS. 19A and 19B are top views of electromagnetic locking mechanisms ofthe present invention for use with counter-clockwise and clockwiseoperative bolt works mechanisms, respectively; and

FIGS. 20A and 20B are top views of an electromagnetic locking mechanismof the present invention for use with either a counter-clockwise (FIG.20A) or a clockwise operative bolt works mechanism (FIG. 20B).

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the inside surface of a safe door 1 associated with ahandle driven bolt works mechanism 2 whose bolt works members 3, 4 and 5reciprocate between normally protruding locking positions and refractedunlocking positions respectively corresponding to the normally lockedand unlocked states of the door. The bolt works mechanism 2 is so-called“counterclockwise operative” because its bolt works members reciprocatefrom their normally protruding locking positions to their retractedunlocking position on a counterclockwise rotation of a handle 7.Reciprocation of the bolt works mechanism 2 is selectively enabled onentry of an access code via a code entry means 8 by means of a lock 9having a lock bolt 10 snugly received in a recess 11 formed in boltworks member 3.

FIG. 2 shows the inside surface of a safe door 13 having a code entrymeans 14 and a handle 15 for directly locking and unlocking a lock 16having a lock bolt 17 and a pair of locking members 19 and 20respectively connected to locking bolts 21, 22 and 23, the locking bolts21, 22 and 23 reciprocating between normally protruding lockingpositions and retracted unlocking positions respectively correspondingto normally locked and unlocked states of the door.

FIGS. 3 and 4 show a lock 25 constituting the locks 9 and 16 andincluding a lock housing 26 having throughbores 27, 28 and 29 enablingits attachment to a safe door by means of three bolts 31, 32 and 33. Thelock housing 26 includes a main block 34 and a cover plate 35 forattachment to the main block 34 by means of screws 37 and 38 received bytapped bores 39 and 40 (see FIG. 4). The main block 34 includes a frontsurface 41 for juxtaposition against a safe door, the front surface 41being formed with four through bores 43, 44, 45 and 46 at one endthereof adjacent a short side wall 47 formed with a generallyrectangular shaped lock bolt aperture 49 and a stop 50 (see FIG. 4).

A two-piece lock bolt 48 corresponding to the lock bolts 10 and 17protrudes through the lock bolt aperture 49. For use in connection withthe safe door 13 of FIG. 2, the main block's front surface 41 is formedwith a aversely disposed channel 51 for receiving the pair of lockingmembers 19 and 20. The locking members 19 and 20 are respectivelypivotally attached to diagonally opposite projections 52 and 53 formedon the underside of a rotatable disk 55 and travel along curved guides57 and 58. The locking members 19 and 20 are held in place by a cover 59secured to the front surface 41 by means of screws 61 and 62 received intapped bores 63 and 64. The rotatable disk 55 has a central squareaperture 56 to which is journaled the handle 15 for rotating therotatable disk 55 for reciprocating the lock bolt 48 and the lockingmembers 19 and 20 between their normally protruding locking position andretracted unlocking positions.

FIGS. 5-7 show that the lock bolt 48 is constituted by a substantiallyP-shaped rotary lock bolt 65 and a substantially right angle shaped lockbolt urging member 67 having complimentary shapes delimiting animaginary square in a top view (see FIG. 6) and having common upper andtower surfaces 68 and 69 (see FIG. 7). The rotary lock bolt 65 has a legportion 70 and a body portion 71 whilst the lock bolt urging member 67has a full width trailing portion 73 and a leading portion 74. The lockbolt urging member 67 is formed with a blind bore 75 for at leastpartially receiving a biasing spring 76 (see FIG. 10).

The body portion 71 has a cam surface 77 which is in continuous abuttingengagement with a leading portion's inclined abutment surface 78 whichis substantially parallel to the imaginary square's diagonal. The camsurface 77 and the abutment surface 78 are formed with a groove 79 andmatching projection 80 for facilitating a more controlled slidingengagement therebetween.

The rotary lock bolt's leg 70 is formed with a threaded through bore 81for receiving a set screw 82 whilst the lock bolt urging memberstrailing portion 73 is formed with a pair of threaded through bores 83and 85 for receiving identical set screws 86 and 87. The bores 81, 83and 85 are such that on the full insertion of the set screws from theunderside, the head of set screw 82 protrudes below the lower surface 69(see FIG. 8) whilst a portion of the set screw 86 protrudes above theupper surface 68 and the head of the set screw 87 protrudes below thelower surface 69 (see FIG. 9).

The complimentary shapes of the locking rotary bolt 65 and the lock bolturging member 67 have co-planar end surfaces 88 and 89 which areprovided with threaded blind bores 91 and 92 by means of which thelocking bolt 21 can be attached (see FIG. 2).

Turning now to FIGS. 10—13, a carriage 95 is formed with a leadingportion 96 and a trailing portion 97 which is stepped relative to theleading portion 96 so as to overlie a portion of the rotatable disk 55.The leading portion 96 is bifurcated with a central web portion 98adapted to abut against the stop 50 and lateral extensions 99 and 101(see FIG. 12). The trailing portion 97 is provided with a notch 102adapted to engage a projection 103 on the topside of the rotatable disk55 such that rotation of the rotatable disk 55 reciprocates the carriage95 between an outward position juxtaposed against the stop 50 and aninward position.

An internal wall structure 104 and a pair of internal walls 106 and 107sideways restrain the carriage 95 during its reciprocation between itsextreme outward and inward positions. A U-shaped spring 108 having oneleg 109 received in an aperture 111 formed in the carriage's trailingportion 97 and its other leg 112 received in an aperture 113 formed inthe internal wall structure 104 is normally biased into an open positionin either one of the carriage's extreme positions.

The lateral extension 99 is formed with a pair of through bores 114 and116 and the lateral extension 101 is formed with a single through bore117 and a cutaway section 118. During assembly when the carriage'scentral web 98 is juxtaposed against the stop 50, the through bores 114,116 and 117 respectively overlay the through bores 45, 46 and 43 whilstthe cutaway section 118 overlays the through bore 44 thereby enablinginsertion of the set screws 82, 86 and 87 from the main block's frontsurface 41.

A right angled flange 119 is provided on the one hand, for securing therotatable disk 55 and, on the second hand, providing a storagecompartment for batteries 120. The internal wall 106 is provided with asupport rod 121 on which the biasing spring 76 is mounted.

A lock bolt arresting member 122 together with the rotary lock bolt 65and the lock bolt urging member 67 overlay the carriage 95. The lockbolt arresting member 122 is formed with a stepped leading portion 123,an intermediate portion 124 and a recessed trailing portion 126. Thestepped leading portion 123 is configured to receive the left side ofthe trailing portion 73 of the lock bolt urging member 67 and is formedwith a threaded through bore 127 for receiving the upwardly protrudingportion of the set screw 86 (see FIG. 15) whereby the spring biased lockbolt urging member 67 and the 10 lock bolt arresting member 122constitute a lock bolt urging mechanism 128 (see FIG. 12).

Under the action of the biasing spring 76, the lock bolt urgingmechanism 128 is urged into a normally outwardly biased position whichin turn urges the rotary lock bolt 65 into its normally protrudinglocking position. On a rotation force applied to the rotary lock bolt65, it rotates about the set screw 82 which resides in the through bore114 (see FIG. 14) so as to substantially flush with the side surface 47in its retracted unlocking position thereby causing he lock bolt urgingmechanism 128 into its retracted position against the internal wall 106.True reciprocation of the lock bolt urging mechanism 128 is facilitatedby the set screw 87 sliding along the side surface of the cutawaysection 118.

A magnetically latched solenoid 129 with an armature 131 is under thecontrol of a controller 132 connected to a code entry means 133 (seeFIG. 10). The armature 131 is reciprocable in a direction perpendicularto the direction of reciprocation of the lock bolt urging mechanism 128between a retracted unblocking position and an outwardly biased blockingdisposed toward either the lock bolt arresting member's intermediate ortrailing portions 124 and 126 depending on the latter's positionrelative thereto.

FIG. 16 shows that tie lock 25 can be adapted for use with a clockwiseoperative bolt works mechanism by virtue of the positions of the rotarylock bolt 65 and the lock bolt urging member 67 be reversed. In thiscase, the rotary lock bolt 65 is rotatably mounted via a set screwinserted through the through bore 43 whilst the other two set screwsreceived by the lock bolt urging member 67 are inserted through thebores 44 and 46 in the manner described above.

The operation of the lock 9 of FIG. 1 is now described with reference toFIGS. 17A-17F. In the normal state of the lock 9, the lock bolt 10 is inits protruding position, the lock bolt urging mechanism 128 is in itsoutwardly biased position, the carriage 95 is disposed toward the lockbolt aperture 49 and the solenoid armature 131 is its outwardly biasedblocking position against the lock bolt arresting member's trailingportion 126 (see FIG. 17A). In the event of an attempted unauthorizedentry, a force applied to the lock bolt 10 is mainly dissipated by meansof the lock bolt urging member 67 being urged against different internalstructures thereby considerably reducing the force applied against thearmature 131.

On entry of the access code, the solenoid 129 is activated whereby itsarmature 131 is magnetically latched into its retracted unblockingposition (see FIG. 17B). The armature 131 is latched for sufficient timethat the bolt works mechanism can be manipulated to open the safe door,namely, to displace the bolt works member 3 downward (see FIG. 17C)whereby the rotary lock bolt 65 is forcibly rotated to its retractedunlocking position causing the rearward displacement of the lock bolturging mechanism 128 (see FIG. 17D). The force required to push therotary lock bolt 65 into its retracted unlocking position graduallydecreases because the force acts over a longer arm as the cam surface 77slides along the abutment surface 78.

Whilst the safe door is opened, the solenoid 129 is activated a secondtime for urging its armature 131 to its outwardly biased blockingposition. However, instead of the armatures 131 being biased againstlock bolt arresting member's trailing portion 126, it is biased againstits intermediate portion 124 because the rotary lock bolt 65 isretracted (see FIG. 17E). The armature 131 is biased against thetrailing portion 126 when the bolt works mechanism is manipulated todisplace the bolt 3 upward to lock the safe door (see FIG. 17F).

The operation of the lock 16 of FIG. 2 is now described with referenceto FIGS. 18A-18F. In the normal state of the lock 16, the lock bolt 17is in its protruding position, the lock bolt urging mechanism 128 is inits outwardly biased position, the carriage 95 is disposed toward thelock bolt aperture 49 and the armature 131 is its outwardly biasedblocking position against the lock bolt arresting member's trailingportion 126 (see FIG. 18A). In this arrangement, the armature 131 takesup most of a horizontally force applied against lock bolt 17 in anattempted unauthorized opening of the lock.

On entry of the access code, the solenoid 129 is activated whereby itsarmature 131 is magnetically latched in its retracted unblockingposition (see FIG. 18B). The armature 131 is latched for sufficient timeto open the safe door, namely, by rotating the handle 15counterclockwise to urge the lock bolt 17 and the locking members 19 and20 into their retracted unlocking positions (see FIG. 18C). On theurging of the rotary lock bolt 65 backwards, the lock bolt urgingmechanism 128 merely rides with the movement of the carriage 95.

Once the door is open, the solenoid 129 is activated a second time forurging its armature 131 to its outwardly biased blocking position.However, instead of the armature 131 being biased against lock boltarresting member's trailing portion 126, it is biased against theintermediate portion 124 because the rotary lock bolt 65 is in itsretracted unlocking position (see FIG. 18D). The armature 131 is biasedagainst the trailing portion 126 when the handle 15 is rotates clockwiseto lock the safe door (see FIG. 18E).

While the invention has been described with respect to a limited numberof embodiments, it will be appreciated that many variations,modifications and other applications of the invention can be madewithout departing from the scope of the claims appended hereto. Forexample, FIGS. 19A and 19B show electromagnetic locking mechanisms 134and 136 with their lock bolt urging members 67 integrally formed withtheir lock bolt arresting members 122 for use in counter-clockwiseoperative and clockwise operative bolt works mechanisms, respectively.FIGS. 20A and 20B show an electromagnetic locking mechanism 137 havingits lock bolt urging member 67 detachably attached to its lock boltarresting member 122 for use in a counter-clockwise operative bolt worksmechanism (FIG. 20A) or a clockwise operative bolt works mechanism (FIG.20B).

What is claimed is:
 1. An electromagnetic locking mechanism comprising:(a) a rotary lock bolt rotatably reciprocable between a normallyprotruding locking position relative to a lock bolt aperture and aretracted unlocking position on a forced rotation thereof by an externalopening force; (b) urging means for normally urging said rotary lockbolt to said normally protruding locking position; (c) a blocking memberreciprocable between a blocking position and an unblocking position forrespectively preventing and enabling said forced rotation of said rotarylock bolt; characterized in that said rotary lock bolt has a camsurface, said urging means is constituted by a lock bolt urging memberhaving a leading portion with an abutment surface in continuous abuttingengagement with said cam surface, and being linearly reciprocable from anormally protruding biased position relative to said lock bolt aperturefor urging said rotary bolt to said normally protruding locking positionto a retracted position in a single continuous movement during saidforced rotation of said rotary lock bolt, said leading portion and saidrotary lock bolt delimit an imaginary square having a diagonalsubstantially parallel to said abutment surface, and said blockingmember prevents a rearward displacement of said lock bolt urging memberfrom said normally protruding biased position to said retracted positionin said blocking position and enables said rearward displacement in saidunblocking position, further including electromagnetic means operativelycoupled to said blocking member which when energized causes saidblocking member to shift from said blocking position to said unblockingposition.
 2. The mechanism according to claim 1 wherein said abutmentsurface traverses said lock bolt aperture in said normally protrudingbiased position.
 3. The mechanism according to claim 1 wherein saidrotary lock bolt is substantially P-shaped.
 4. The mechanism accordingto claim 1 wherein said abutment surface and said cam surface are formedwith a groove and a matching projection for a more controlled slidinginterengagement therebetween.
 5. The mechanism according to claim 1wherein said blocking member is operatively associated with a lock boltarresting member coupled to said lock bolt urging member and is linearlyreciprocable in a transverse direction to the direction of reciprocationof said lock bolt urging member.
 6. The mechanism according to claim 5wherein said lock bolt urging member and said lock bolt arresting memberare integrally formed.
 7. The member according to claim 5 wherein saidlock bolt urging member is detachably coupled to said lock boltarresting member whereby the positions of said rotary lock bolt and saidlock bolt urging member are interchangeable such that the mechanism iscapable for use with either a clockwise or a counterclockwise operativebolt works mechanism.
 8. The mechanism according to claim 1 furthercomprising a handle operated carriage linearly reciprocable betweenoutward and inward positions for selectively displacing said rotary lockbolt between said normally protruding locking position and a secondretracted unlocking position and wherein said blocking memberselectively enables a rearward displacement of said carriage from saidoutward position to said inward position.
 9. A locking mechanism as setforth in claim 1, wherein said electromagnetic means is operativelycoupled to a code entry means that permits the electromagnetic means tobe energized only when a predetermined code is entered therein.